Spirochete disease in humans can often be characterized by a wide range of clinical manifestations which may include fever, chills, fatigue, neurological, musculoskeletal and cardiac symptoms. These symptoms can appear at regular intervals in the case of relapsing fever or they can occur infrequently and intermittently as in the case of Lyme disease and syphilis. This wide range of symptoms may be due to dissemination of the spirochetes throughout the vasculature of the host to various tissues and organs. Interestingly, a chronic form of Lyme disease is thought to persist long after conventional antibiotic treatment. Symptoms such as musculoskeletal pain, fatigue, and memory loss appear to persist in the apparent absence of isolatable spirochetes. Recently, several technological advancements have been made in the field of biotelemetry that allow for the first time the opportunity to analyze temperature, activity, and in the very near future, heart rate, in the infected mouse over the life of the animal. We are in the process of setting up this technology which will allow us to analyze relapsing fever, chronic Lyme borreliosis, and potentially syphilis sequela in the laboratory mouse. The potential also exists for us to analyze the long term chronically infected animal before, during, and after antibiotic treatment. The information gained from these studies will be important towards providing new data on the clinical symptomology of these spirochetal diseases in the mouse. Quantitative clinical symptomology data used in conjunction with a variety of molecular and immunological analyses should allow further study and determination of those molecules or mechanisms of the pathogen which produce such host responses.